1. Field of the Invention
The present invention relates to refrigeration systems which are adapted to cool a fluid for domestic or other uses. More particularly the present invention relates to refrigeration systems wherein a flash type subcooler is utilized to subcool liquid refrigerant by changing part of the liquid refrigerant to a gas thereby absorbing heat from the remaining liquid refrigerant.
2. Description of the Prior Art
Refrigerant systems of a vapor compression type typically employ a compressor to increase the temperature and pressure of the gaseous refrigerant. Connected thereto is a condenser wherein the gaseous refrigerant is cooled so it changes state to a liquid refrigerant. Thereafter the refrigerant may be subcooled in a flash economizer wherein a part of the refrigerant is vaporized absorbing heat from the remaining liquid refrigerant. The vaporized refrigerant has been typically drawn into the compressor for recycling through the condenser and the liquid refrigerant which has now been cooled passes on to the evaporator or chiller. In the chiller refrigerant is evaporated absorbing heat from the fluid to be cooled, the now gaseous refrigerant being drawn into the compressor to complete the cycle. In the above described refrigeration system the compressor is a multi-stage compressor such that the flashed refrigerant from the flash economizer may be drawn into the compressor between stages allowing the flash economizer to be at an intermediate pressure to the condenser such to the chiller. The basic patent dealing with the flash economizer was issued to Jones in 1942 and is entitled "Refrigeration", U.S. Pat. No. 2,277,647.
Other methods of removing flashed refrigerant gas from a flash economizer have been developed. These include recondensing the flashed gas within the flash economizer or subcooler by the use of an economizer condenser supplied with relatively cool condensing fluid. A combination of an economizer condenser and a compressor may be used such that the flashed refrigerant gas is artially condensed by the economizer condenser and the remainder removed by the compressor. Also flashed refrigerant gas has been removed by a second compressor, said gas is then recondensed by an economizer condenser such that the now liquid refrigerant may be used within the chiller of the refrigeration system. For a better explanation of these various ideas see United States Patent Application entitled "Dual Flash Economizer Refrigeration System", Ser. No. 828,458; "Thermal Economized Refrigeration System", Ser. No. 828,449; "Supply Water Cooling in a Refrigeration System", Ser. No. 828,810; "Thermal Economizer Application for a Centrifugal Refrigeration Machine", Ser. No. 828,448; and "Dual Flash and Thermal Economized Refrigeration System", Ser. No. 828,793, all filed simultaneously herewith and all assigned to the assignee hereof.
The subcooler or flash economizer for use within the above referenced systems normally has an economizer condenser mounted at the top thereof so that rising refrigerant gas may be condensed thereon. A reservoir is provided in the bottom of the subcooler such that a liquid refrigerant may be collected and conducted to the next component in the refrigeration system. A means for flashing the liquid refrigerant into the flash economizer is provided in the middle of the flash economizer such that the flashed gas may rise and a liquid refrigerant may fall to the bottom thereof.
The particular apparatus hereafter described uses a distribution box having perforated end plates to evenly distribute flashed refrigerant gas throughout the economizer condenser. In Zwickl, U.S. Pat. No. 2,274,391, openings are provided in an evaporator for distribution of flashed refrigerant gas. However there is no flow of liquid refrigerant through the openings or through the distribution box but merely a guide path such that gaseous refrigerant is withdrawn by the compressor evenly throughout the evaporator. Furthermore this evaporator is not a subcooler and does not have a condensing coil located such that the gaseous refrigerant will be condensed thereon within that pressure vessel.
The flash economizer or subcooler described herein is adapted to be utilized with a single-stage or multi-stage existing or new refrigeration machine. This flash economizer is particularly adaptable for retrofit machinery to provide a flash economizing step without the addition of an additional compressor. This flash economizer utilizing an economizer condenser with a cool water supply also operates to increase the refrigeration system efficiency and simultaneously may be utilized to preheat building supply water.